ACPI / PMIC: support PMIC operation region for CrystalCove

The Baytrail-T platform firmware has defined two customized operation
regions for PMIC chip Crystal Cove - one is for power resource handling
and one is for thermal: sensor temperature reporting, trip point setting,
etc. This patch adds support for them on top of the existing Crystal Cove
PMIC driver.

The reason to split code into a separate file intel_pmic.c is that there
are more PMIC drivers with ACPI operation region support coming and we can
re-use those code. The intel_pmic_opregion_data structure is created also
for this purpose: when we need to support a new PMIC's operation region,
we just need to fill those callbacks and the two register mapping tables.

Signed-off-by: Aaron Lu <aaron.lu@intel.com>
Acked-by: Lee Jones <lee.jones@linaro.org> for the MFD part
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

1 files changed, 354 insertions, 0 deletions

diff --git a/drivers/acpi/pmic/intel_pmic.c b/drivers/acpi/pmic/intel_pmic.c
new file mode 100644
index 000000000000..a732e5d7e322
--- /dev/null
+++ b/drivers/acpi/pmic/intel_pmic.c
@@ -0,0 +1,354 @@
+/*
+ * intel_pmic.c - Intel PMIC operation region driver
+ *
+ * Copyright (C) 2014 Intel Corporation. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License version
+ * 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/module.h>
+#include <linux/acpi.h>
+#include <linux/regmap.h>
+#include "intel_pmic.h"
+
+#define PMIC_POWER_OPREGION_ID		0x8d
+#define PMIC_THERMAL_OPREGION_ID	0x8c
+
+struct acpi_lpat {
+	int temp;
+	int raw;
+};
+
+struct intel_pmic_opregion {
+	struct mutex lock;
+	struct acpi_lpat *lpat;
+	int lpat_count;
+	struct regmap *regmap;
+	struct intel_pmic_opregion_data *data;
+};
+
+static int pmic_get_reg_bit(int address, struct pmic_table *table,
+			    int count, int *reg, int *bit)
+{
+	int i;
+
+	for (i = 0; i < count; i++) {
+		if (table[i].address == address) {
+			*reg = table[i].reg;
+			if (bit)
+				*bit = table[i].bit;
+			return 0;
+		}
+	}
+	return -ENOENT;
+}
+
+/**
+ * raw_to_temp(): Return temperature from raw value through LPAT table
+ *
+ * @lpat: the temperature_raw mapping table
+ * @count: the count of the above mapping table
+ * @raw: the raw value, used as a key to get the temerature from the
+ *       above mapping table
+ *
+ * A positive value will be returned on success, a negative errno will
+ * be returned in error cases.
+ */
+static int raw_to_temp(struct acpi_lpat *lpat, int count, int raw)
+{
+	int i, delta_temp, delta_raw, temp;
+
+	for (i = 0; i < count - 1; i++) {
+		if ((raw >= lpat[i].raw && raw <= lpat[i+1].raw) ||
+		    (raw <= lpat[i].raw && raw >= lpat[i+1].raw))
+			break;
+	}
+
+	if (i == count - 1)
+		return -ENOENT;
+
+	delta_temp = lpat[i+1].temp - lpat[i].temp;
+	delta_raw = lpat[i+1].raw - lpat[i].raw;
+	temp = lpat[i].temp + (raw - lpat[i].raw) * delta_temp / delta_raw;
+
+	return temp;
+}
+
+/**
+ * temp_to_raw(): Return raw value from temperature through LPAT table
+ *
+ * @lpat: the temperature_raw mapping table
+ * @count: the count of the above mapping table
+ * @temp: the temperature, used as a key to get the raw value from the
+ *        above mapping table
+ *
+ * A positive value will be returned on success, a negative errno will
+ * be returned in error cases.
+ */
+static int temp_to_raw(struct acpi_lpat *lpat, int count, int temp)
+{
+	int i, delta_temp, delta_raw, raw;
+
+	for (i = 0; i < count - 1; i++) {
+		if (temp >= lpat[i].temp && temp <= lpat[i+1].temp)
+			break;
+	}
+
+	if (i == count - 1)
+		return -ENOENT;
+
+	delta_temp = lpat[i+1].temp - lpat[i].temp;
+	delta_raw = lpat[i+1].raw - lpat[i].raw;
+	raw = lpat[i].raw + (temp - lpat[i].temp) * delta_raw / delta_temp;
+
+	return raw;
+}
+
+static void pmic_thermal_lpat(struct intel_pmic_opregion *opregion,
+			      acpi_handle handle, struct device *dev)
+{
+	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
+	union acpi_object *obj_p, *obj_e;
+	int *lpat, i;
+	acpi_status status;
+
+	status = acpi_evaluate_object(handle, "LPAT", NULL, &buffer);
+	if (ACPI_FAILURE(status))
+		return;
+
+	obj_p = (union acpi_object *)buffer.pointer;
+	if (!obj_p || (obj_p->type != ACPI_TYPE_PACKAGE) ||
+	    (obj_p->package.count % 2) || (obj_p->package.count < 4))
+		goto out;
+
+	lpat = devm_kmalloc(dev, sizeof(int) * obj_p->package.count,
+			    GFP_KERNEL);
+	if (!lpat)
+		goto out;
+
+	for (i = 0; i < obj_p->package.count; i++) {
+		obj_e = &obj_p->package.elements[i];
+		if (obj_e->type != ACPI_TYPE_INTEGER) {
+			devm_kfree(dev, lpat);
+			goto out;
+		}
+		lpat[i] = (s64)obj_e->integer.value;
+	}
+
+	opregion->lpat = (struct acpi_lpat *)lpat;
+	opregion->lpat_count = obj_p->package.count / 2;
+
+out:
+	kfree(buffer.pointer);
+}
+
+static acpi_status intel_pmic_power_handler(u32 function,
+		acpi_physical_address address, u32 bits, u64 *value64,
+		void *handler_context, void *region_context)
+{
+	struct intel_pmic_opregion *opregion = region_context;
+	struct regmap *regmap = opregion->regmap;
+	struct intel_pmic_opregion_data *d = opregion->data;
+	int reg, bit, result;
+
+	if (bits != 32 || !value64)
+		return AE_BAD_PARAMETER;
+
+	if (function == ACPI_WRITE && !(*value64 == 0 || *value64 == 1))
+		return AE_BAD_PARAMETER;
+
+	result = pmic_get_reg_bit(address, d->power_table,
+				  d->power_table_count, &reg, &bit);
+	if (result == -ENOENT)
+		return AE_BAD_PARAMETER;
+
+	mutex_lock(&opregion->lock);
+
+	result = function == ACPI_READ ?
+		d->get_power(regmap, reg, bit, value64) :
+		d->update_power(regmap, reg, bit, *value64 == 1);
+
+	mutex_unlock(&opregion->lock);
+
+	return result ? AE_ERROR : AE_OK;
+}
+
+static int pmic_read_temp(struct intel_pmic_opregion *opregion,
+			  int reg, u64 *value)
+{
+	int raw_temp, temp;
+
+	if (!opregion->data->get_raw_temp)
+		return -ENXIO;
+
+	raw_temp = opregion->data->get_raw_temp(opregion->regmap, reg);
+	if (raw_temp < 0)
+		return raw_temp;
+
+	if (!opregion->lpat) {
+		*value = raw_temp;
+		return 0;
+	}
+
+	temp = raw_to_temp(opregion->lpat, opregion->lpat_count, raw_temp);
+	if (temp < 0)
+		return temp;
+
+	*value = temp;
+	return 0;
+}
+
+static int pmic_thermal_temp(struct intel_pmic_opregion *opregion, int reg,
+			     u32 function, u64 *value)
+{
+	return function == ACPI_READ ?
+		pmic_read_temp(opregion, reg, value) : -EINVAL;
+}
+
+static int pmic_thermal_aux(struct intel_pmic_opregion *opregion, int reg,
+			    u32 function, u64 *value)
+{
+	int raw_temp;
+
+	if (function == ACPI_READ)
+		return pmic_read_temp(opregion, reg, value);
+
+	if (!opregion->data->update_aux)
+		return -ENXIO;
+
+	if (opregion->lpat) {
+		raw_temp = temp_to_raw(opregion->lpat, opregion->lpat_count,
+				       *value);
+		if (raw_temp < 0)
+			return raw_temp;
+	} else {
+		raw_temp = *value;
+	}
+
+	return opregion->data->update_aux(opregion->regmap, reg, raw_temp);
+}
+
+static int pmic_thermal_pen(struct intel_pmic_opregion *opregion, int reg,
+			    u32 function, u64 *value)
+{
+	struct intel_pmic_opregion_data *d = opregion->data;
+	struct regmap *regmap = opregion->regmap;
+
+	if (!d->get_policy || !d->update_policy)
+		return -ENXIO;
+
+	if (function == ACPI_READ)
+		return d->get_policy(regmap, reg, value);
+
+	if (*value != 0 && *value != 1)
+		return -EINVAL;
+
+	return d->update_policy(regmap, reg, *value);
+}
+
+static bool pmic_thermal_is_temp(int address)
+{
+	return (address <= 0x3c) && !(address % 12);
+}
+
+static bool pmic_thermal_is_aux(int address)
+{
+	return (address >= 4 && address <= 0x40 && !((address - 4) % 12)) ||
+	       (address >= 8 && address <= 0x44 && !((address - 8) % 12));
+}
+
+static bool pmic_thermal_is_pen(int address)
+{
+	return address >= 0x48 && address <= 0x5c;
+}
+
+static acpi_status intel_pmic_thermal_handler(u32 function,
+		acpi_physical_address address, u32 bits, u64 *value64,
+		void *handler_context, void *region_context)
+{
+	struct intel_pmic_opregion *opregion = region_context;
+	struct intel_pmic_opregion_data *d = opregion->data;
+	int reg, result;
+
+	if (bits != 32 || !value64)
+		return AE_BAD_PARAMETER;
+
+	result = pmic_get_reg_bit(address, d->thermal_table,
+				  d->thermal_table_count, &reg, NULL);
+	if (result == -ENOENT)
+		return AE_BAD_PARAMETER;
+
+	mutex_lock(&opregion->lock);
+
+	if (pmic_thermal_is_temp(address))
+		result = pmic_thermal_temp(opregion, reg, function, value64);
+	else if (pmic_thermal_is_aux(address))
+		result = pmic_thermal_aux(opregion, reg, function, value64);
+	else if (pmic_thermal_is_pen(address))
+		result = pmic_thermal_pen(opregion, reg, function, value64);
+	else
+		result = -EINVAL;
+
+	mutex_unlock(&opregion->lock);
+
+	if (result < 0) {
+		if (result == -EINVAL)
+			return AE_BAD_PARAMETER;
+		else
+			return AE_ERROR;
+	}
+
+	return AE_OK;
+}
+
+int intel_pmic_install_opregion_handler(struct device *dev, acpi_handle handle,
+					struct regmap *regmap,
+					struct intel_pmic_opregion_data *d)
+{
+	acpi_status status;
+	struct intel_pmic_opregion *opregion;
+
+	if (!dev || !regmap || !d)
+		return -EINVAL;
+
+	if (!handle)
+		return -ENODEV;
+
+	opregion = devm_kzalloc(dev, sizeof(*opregion), GFP_KERNEL);
+	if (!opregion)
+		return -ENOMEM;
+
+	mutex_init(&opregion->lock);
+	opregion->regmap = regmap;
+	pmic_thermal_lpat(opregion, handle, dev);
+
+	status = acpi_install_address_space_handler(handle,
+						    PMIC_POWER_OPREGION_ID,
+						    intel_pmic_power_handler,
+						    NULL, opregion);
+	if (ACPI_FAILURE(status))
+		return -ENODEV;
+
+	status = acpi_install_address_space_handler(handle,
+						    PMIC_THERMAL_OPREGION_ID,
+						    intel_pmic_thermal_handler,
+						    NULL, opregion);
+	if (ACPI_FAILURE(status)) {
+		acpi_remove_address_space_handler(handle, PMIC_POWER_OPREGION_ID,
+						  intel_pmic_power_handler);
+		return -ENODEV;
+	}
+
+	opregion->data = d;
+	return 0;
+}
+EXPORT_SYMBOL_GPL(intel_pmic_install_opregion_handler);
+
+MODULE_LICENSE("GPL");